Iontophoretic administration of dexamethasone sodium phosphate for acute epicondylitis. A randomized, double-blinded, placebo-controlled study.

BACKGROUND: A better treatment modality is needed to control the pain of medial or lateral epicondylitis (tennis elbow).

HYPOTHESIS: Dermal iontophoretic administration of dexamethasone sodium phosphate will be significantly more effective in controlling pain than a placebo in patients with medial or lateral elbow epicondylitis.

STUDY DESIGN: Randomized, double-blinded, placebo-controlled study.

METHODS: On six occasions, 1 to 3 days apart within 15 days, 199 patients with elbow epicondylitis received 40 mA-minutes of either active or placebo treatment.

RESULTS: Dexamethasone produced a significant 23-mm improvement on the 100-mm patient visual analog scale ratings, compared with 14 mm for placebo at 2 days and 24 mm compared with 19 mm at 1 month. More patients treated with dexamethasone than those treated with placebo scored moderate or better on the investigator's global improvement scale (52% versus 33%) at 2 days, but the difference was not significant at 1 month (54% versus 49%). Investigator-rated pain and tenderness scores favored dexamethasone over placebo at 2 days. Patients completing six treatments in 10 days or less had better results than those treated over a longer period.

CONCLUSIONS: Iontophoresis treatment was well tolerated by most patients and was effective in reducing symptoms of epicondylitis at short-term follow-up.